Samsung has started rolling out another Android 4.3 firmware build numbers I9300XXUGMK6 for Samsung Galaxy S3 (GT-I9300) international variants. This update now includes with lots of new improvements after having some undesirable outcomes to the first 4.3 update (I9300XXUGMJ9). The I9300XXUGMK6 is believed to be the solution and resolves some certain issues found on the earlier 4.3 releases. But as of now this update is only available in United Kingdom and several carrier branded Galaxy S3 I9300 devices European countries. The only unbranded Galaxy S3 found receiving this update are those in UK’s Galaxy S3. So to other countries have had may still have to wait for a while until this said I9300XXUGMK6 4.3 update build arrives in your regions.

Here’s the official changelog of I9300XXUGMK6 as addressed by Samsung. This can be seen on Kies software update tool once users will perform the update using Kies.

*You cannot downgrade back to the old software after this new software upgrade due to security reason.

Noting that it’s the same features introduced a while back since the first 4.3 build released. And there’s a direct message in there that you will not be able to downgrade back to the old firmware version once you took this update. For those may have only known about the security enhancement, this is due to the new KNOX added to the system and a secured bootloader that cannot be rewritten easily.

For those advanced users who knows how to flash the stock firmware, yo can actually grab the original I9300XXUGMK6 below. From here you can directly update your Galaxy S3 to official Android 4.3 I9300XXUGMK6 without waiting to when it arrives in your country. This also useful for those who have rooted their Galaxy S3 and can’t get this update on Kies or over-the-air (OTA) . Since you are about to install a official firmware, you’ll lost root after this process but you can find another root method again that works on this update.

Install I9300XXUGMK6 Android 4.3 Jelly Bean

Disclaimer: Use of this method is solely at your own risk!

Make sure that your phone is fully charge.

Back up all important files stored from the device

Use Windows based computer or laptop, Odin will not work on MAC and LINUX.

1. Download the stock firmware I9300XXUGMK6 from here. [link-1 | link-2 |
2. Grab Odin3_v3.09 and Run it in your computer. link
3. Download and install the USB driver. link
– Make sure NOT TO CHECK the “Repartition” option.
4. Click on the AP the button then browse to the tar file.
5. Set your phone in download mode (Turn off phone, then hold Volume Down+Home+Power button simultaneously) Then it ask you to press a Volume Up button to continue.
6. Connect the phone to your computer
7. Hit the “START” button to begin flashing.
8. Wait until it finishes flashing, you can see a word “PASS” once its successfully completes.
9. Wait until the phone completely reboots.
10. Done! Disconnect it from the computer .

Fixing possible errors

I got bootloops or just stuck on logo. Do this, turn the device off, then press Vol Up+Home+Power button to boot into recovery manually. Select wipe data factory reset (Use volume keys to toggle and power button to enter), then reboot.